Yes, I agree @lak that mileage WILL vary based on multiple conditions, one of which being the exact power cable used. I can only provide testimony about my sealed, 500w rms, class D powered sub which is plugged into a power conditioner outlet that provides up to 55 amps of current when needed. The sound quality of the sub was audibly affected in different ways by each power cable I tested, which ranged in price from a few dollars to about $800 (most of which were in the middle of that range).
As far as the response from REL, I’m really not interested in what most manufacturers would tell their retail customers regarding sonic changes due to power cable upgrades. It’s usually not in their financial interest to suggest that may sound significantly better when the power cable is upgraded, potentially implying to certain customers that’s it inadequate as sold.
I have a high level of confidence in my own subjective discrimination of sonic attributes, so what the REL guy said makes no difference to me, personally.
